3
3
* Password-prompt - Read a password from the terminal and print it
5
* Copyright © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 Björn Påhlsson
5
* Copyright © 2008-2013 Teddy Hogeborn
6
* Copyright © 2008-2013 Björn Påhlsson
8
8
* This program is free software: you can redistribute it and/or
9
9
* modify it under the terms of the GNU General Public License as
19
19
* along with this program. If not, see
20
20
* <http://www.gnu.org/licenses/>.
22
* Contact the authors at <mandos@fukt.bsnet.se>.
22
* Contact the authors at <mandos@recompile.se>.
25
#define _GNU_SOURCE /* getline() */
25
#define _GNU_SOURCE /* getline(), asprintf() */
27
#include <termios.h> /* struct termios, tcsetattr(),
27
#include <termios.h> /* struct termios, tcsetattr(),
28
28
TCSAFLUSH, tcgetattr(), ECHO */
29
29
#include <unistd.h> /* struct termios, tcsetattr(),
30
30
STDIN_FILENO, TCSAFLUSH,
31
tcgetattr(), ECHO, readlink() */
32
32
#include <signal.h> /* sig_atomic_t, raise(), struct
33
33
sigaction, sigemptyset(),
34
34
sigaction(), sigaddset(), SIGINT,
35
35
SIGQUIT, SIGHUP, SIGTERM,
37
37
#include <stddef.h> /* NULL, size_t, ssize_t */
38
#include <sys/types.h> /* ssize_t */
38
#include <sys/types.h> /* ssize_t, struct dirent, pid_t,
39
40
#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,
42
#include <dirent.h> /* scandir(), alphasort() */
41
43
#include <stdio.h> /* fprintf(), stderr, getline(),
42
stdin, feof(), fputc()
44
stdin, feof(), fputc(), vfprintf(),
44
46
#include <errno.h> /* errno, EBADF, ENOTTY, EINVAL,
45
47
EFAULT, EFBIG, EIO, ENOSPC, EINTR
47
49
#include <error.h> /* error() */
48
50
#include <iso646.h> /* or, not */
49
51
#include <stdbool.h> /* bool, false, true */
50
#include <string.h> /* strlen, rindex */
52
#include <inttypes.h> /* strtoumax() */
53
#include <sys/stat.h> /* struct stat, lstat(), open() */
54
#include <string.h> /* strlen, rindex, memcmp, strerror()
51
56
#include <argp.h> /* struct argp_option, struct
52
57
argp_state, struct argp,
53
58
argp_parse(), error_t,
55
60
ARGP_ERR_UNKNOWN */
56
61
#include <sysexits.h> /* EX_SOFTWARE, EX_OSERR,
57
62
EX_UNAVAILABLE, EX_IOERR, EX_OK */
63
#include <fcntl.h> /* open() */
64
#include <stdarg.h> /* va_list, va_start(), ... */
59
66
volatile sig_atomic_t quit_now = 0;
60
67
int signal_received;
61
68
bool debug = false;
62
69
const char *argp_program_version = "password-prompt " VERSION;
63
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
70
const char *argp_program_bug_address = "<mandos@recompile.se>";
72
/* Needed for conflict resolution */
73
const char plymouth_name[] = "plymouthd";
75
/* Function to use when printing errors */
76
__attribute__((format (gnu_printf, 3, 4)))
77
void error_plus(int status, int errnum, const char *formatstring,
83
va_start(ap, formatstring);
84
ret = vasprintf(&text, formatstring, ap);
86
fprintf(stderr, "Mandos plugin %s: ",
87
program_invocation_short_name);
88
vfprintf(stderr, formatstring, ap);
89
fprintf(stderr, ": %s\n", strerror(errnum));
90
error(status, errno, "vasprintf while printing error");
93
fprintf(stderr, "Mandos plugin ");
94
error(status, errnum, "%s", text);
65
98
static void termination_handler(int signum){
70
103
signal_received = signum;
106
bool conflict_detection(void){
108
/* plymouth conflicts with password-prompt since both want to read
109
from the terminal. Password-prompt will exit if it detects
110
plymouth since plymouth performs the same functionality.
112
__attribute__((nonnull))
113
int is_plymouth(const struct dirent *proc_entry){
120
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
122
if(errno != 0 or *tmp != '\0'
123
or proc_id != (uintmax_t)((pid_t)proc_id)){
128
char *cmdline_filename;
129
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
132
error_plus(0, errno, "asprintf");
136
/* Open /proc/<pid>/cmdline */
137
cl_fd = open(cmdline_filename, O_RDONLY);
138
free(cmdline_filename);
141
error_plus(0, errno, "open");
146
char *cmdline = NULL;
148
size_t cmdline_len = 0;
149
size_t cmdline_allocated = 0;
151
const size_t blocksize = 1024;
154
/* Allocate more space? */
155
if(cmdline_len + blocksize + 1 > cmdline_allocated){
156
tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
158
error_plus(0, errno, "realloc");
164
cmdline_allocated += blocksize;
168
sret = read(cl_fd, cmdline + cmdline_len,
169
cmdline_allocated - cmdline_len);
171
error_plus(0, errno, "read");
176
cmdline_len += (size_t)sret;
180
error_plus(0, errno, "close");
184
cmdline[cmdline_len] = '\0'; /* Make sure it is terminated */
186
/* we now have cmdline */
189
char *cmdline_base = strrchr(cmdline, '/');
190
if(cmdline_base != NULL){
191
cmdline_base += 1; /* skip the slash */
193
cmdline_base = cmdline;
196
if(strcmp(cmdline_base, plymouth_name) != 0){
198
fprintf(stderr, "\"%s\" is not \"%s\"\n", cmdline_base,
205
fprintf(stderr, "\"%s\" equals \"%s\"\n", cmdline_base,
212
struct dirent **direntries = NULL;
214
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
216
error_plus(1, errno, "scandir");
73
223
int main(int argc, char **argv){
152
303
fprintf(stderr, "Starting %s\n", argv[0]);
306
if(conflict_detection()){
308
fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
155
314
fprintf(stderr, "Storing current terminal attributes\n");
158
317
if(tcgetattr(STDIN_FILENO, &t_old) != 0){
160
error(0, errno, "tcgetattr");
319
error_plus(0, errno, "tcgetattr");
170
329
sigemptyset(&new_action.sa_mask);
171
330
ret = sigaddset(&new_action.sa_mask, SIGINT);
173
error(0, errno, "sigaddset");
332
error_plus(0, errno, "sigaddset");
176
335
ret = sigaddset(&new_action.sa_mask, SIGHUP);
178
error(0, errno, "sigaddset");
337
error_plus(0, errno, "sigaddset");
181
340
ret = sigaddset(&new_action.sa_mask, SIGTERM);
183
error(0, errno, "sigaddset");
342
error_plus(0, errno, "sigaddset");
186
345
/* Need to check if the handler is SIG_IGN before handling:
190
349
ret = sigaction(SIGINT, NULL, &old_action);
192
error(0, errno, "sigaction");
351
error_plus(0, errno, "sigaction");
195
354
if(old_action.sa_handler != SIG_IGN){
196
355
ret = sigaction(SIGINT, &new_action, NULL);
198
error(0, errno, "sigaction");
357
error_plus(0, errno, "sigaction");
202
361
ret = sigaction(SIGHUP, NULL, &old_action);
204
error(0, errno, "sigaction");
363
error_plus(0, errno, "sigaction");
207
366
if(old_action.sa_handler != SIG_IGN){
208
367
ret = sigaction(SIGHUP, &new_action, NULL);
210
error(0, errno, "sigaction");
369
error_plus(0, errno, "sigaction");
214
373
ret = sigaction(SIGTERM, NULL, &old_action);
216
error(0, errno, "sigaction");
375
error_plus(0, errno, "sigaction");
219
378
if(old_action.sa_handler != SIG_IGN){
220
379
ret = sigaction(SIGTERM, &new_action, NULL);
222
error(0, errno, "sigaction");
381
error_plus(0, errno, "sigaction");